The present disclosure relates to a developing device, and to an image forming apparatus provided therewith. More particularly, the present disclosure relates to a developing device including a restricting member for restricting the layer thickness of developer on the surface of a developer carrier, and to an image forming apparatus provided therewith.
Conventionally, there are known, as developing devices for developing an electrostatic latent image on a photosensitive member as an image carrier, those adopting a one-component developing method and those adopting a two-component developing method. The two-component developing method, which uses developer containing toner and magnetic carrier, offers a stable amount of electrostatic charge for a long period and is thus suitable to aim at an extended lifetime. For example, a developing device adopting the two-component developing method accommodates developer containing toner and magnetic carrier, and feeds the developer from a stirring member to a developing roller (developer carrier). The developing roller incorporates a magnet, which carries the developer in the form of a magnetic brush on the surface of the developing roller. As the developing roller rotates, the developer is transported toward the photosensitive member. Out of the developer carried on the developing roller, only the toner is fed to the photosensitive member, and the electrostatic latent image on the photosensitive member is made visible as a toner image.
A developing device as described above is provided with a restricting member for restricting the layer thickness of developer in order to make constant the amount of developer transported, as the developing roller rotates, toward the photosensitive member.
There is also known a developing device comprising a resin-made developing container for storing developer, a stir-transport member for stirring and transporting the developer, a developing roller fed with the developer from the stir-transport member, and a restricting member for restricting the layer thickness of developer on the surface of the developing roller, wherein the restricting member is composed of a restricting base formed integrally with the developing container and a metal member covering a tip part of the restricting base. With this developing device, owing to the use of the metal member in the tip part of the restricting member, it is possible to form the tip part of the restricting member with high accuracy, and to suppress wear in the tip part of the restricting member.